Random.Next 方法

定义

返回一个随机整数。

重载

Next()

返回一个非负随机整数。

Next(Int32)

返回一个小于所指定最大值的非负随机整数。

Next(Int32, Int32)

返回在指定范围内的任意整数。

Next()

返回一个非负随机整数。

public:
 virtual int Next();
public virtual int Next ();
abstract member Next : unit -> int
override this.Next : unit -> int
Public Overridable Function Next () As Integer

返回

Int32

大于或等于 0 且小于 MaxValue 的 32 位有符号整数。

示例

下面的示例对方法进行重复调用 Next ,以生成用户请求的特定数量的随机数字。 Console.ReadLine方法用于获取客户输入。

using namespace System;

void main()
{
   Console::Write("Number of random numbers to generate: ");
   String^ line = Console::ReadLine();
   unsigned int numbers = 0;
   Random^ rnd = gcnew Random();
   
   if (! UInt32::TryParse(line, numbers))
      numbers = 10;
   
   for (unsigned int ctr = 1; ctr <= numbers; ctr++)
      Console::WriteLine("{0,15:N0}", rnd->Next());
}
// The example displays output like the following when asked to generate
// 15 random numbers:
//       Number of random numbers to generate: 15
//         1,733,189,596
//           566,518,090
//         1,166,108,546
//         1,931,426,514
//         1,341,108,291
//         1,012,698,049
//           890,578,409
//         1,377,589,722
//         2,108,384,181
//         1,532,939,448
//           762,207,767
//           815,074,920
//         1,521,208,785
//         1,950,436,671
//         1,266,596,666
Random rnd = new Random();

Console.WriteLine("Generating 10 random numbers:");

for (uint ctr = 1; ctr <= 10; ctr++)
   Console.WriteLine($"{rnd.Next(),15:N0}");

// The example displays output like the following:
//
//     Generating 10 random numbers:
//         1,733,189,596
//           566,518,090
//         1,166,108,546
//         1,931,426,514
//         1,532,939,448
//           762,207,767
//           815,074,920
//         1,521,208,785
//         1,950,436,671
//         1,266,596,666
let rnd = Random()

printfn "Generating 10 random numbers:"

for _ = 1 to 10 do
    printfn $"{rnd.Next(),15:N0}"

// The example displays output like the following:
//
//     Generating 10 random numbers:
//         1,733,189,596
//           566,518,090
//         1,166,108,546
//         1,931,426,514
//         1,532,939,448
//           762,207,767
//           815,074,920
//         1,521,208,785
//         1,950,436,671
//         1,266,596,666
Module Example
   Public Sub Main()
      Console.Write("Number of random numbers to generate: ")
      Dim line As String = Console.ReadLine()
      Dim numbers As UInteger = 0
      Dim rnd As New Random()
      
      If Not UInt32.TryParse(line, numbers) Then numbers = 10
      
      For ctr As UInteger = 1 To numbers  
         Console.WriteLine("{0,15:N0}", rnd.Next())
      Next
   End Sub
End Module
' The example displays output like the following when asked to generate
' 15 random numbers:
'       Number of random numbers to generate: 15
'         1,733,189,596
'           566,518,090
'         1,166,108,546
'         1,931,426,514
'         1,341,108,291
'         1,012,698,049
'           890,578,409
'         1,377,589,722
'         2,108,384,181
'         1,532,939,448
'           762,207,767
'           815,074,920
'         1,521,208,785
'         1,950,436,671
'         1,266,596,666

下面的示例从派生一个类 Random ,以生成一个随机数序列,其分布不同于基类的方法所生成的统一分布 Sample 。 它重写 Sample 方法以提供随机数的分布,并重写 Random.Next 方法以使用随机数字序列。

using namespace System;

// This derived class converts the uniformly distributed random 
// numbers generated by base.Sample() to another distribution.
public ref class RandomProportional : Random
{
    // The Sample method generates a distribution proportional to the value 
    // of the random numbers, in the range [0.0, 1.0].
protected:
   virtual double Sample() override
   {
       return Math::Sqrt(Random::Sample());
   }

public:
   RandomProportional()
   {}
   
   virtual int Next() override
   {
      return (int) (Sample() * Int32::MaxValue);
   }   
};

int main(array<System::String ^> ^args)
{
      const int rows = 4, cols = 6;
      const int runCount = 1000000;
      const int distGroupCount = 10;
      const double intGroupSize = 
         ((double) Int32::MaxValue + 1.0) / (double)distGroupCount;

      RandomProportional ^randObj = gcnew RandomProportional();

      array<int>^ intCounts = gcnew array<int>(distGroupCount);
      array<int>^ realCounts = gcnew array<int>(distGroupCount);

      Console::WriteLine(
         "\nThe derived RandomProportional class overrides " +
         "the Sample method to \ngenerate random numbers " +
         "in the range [0.0, 1.0]. The distribution \nof " +
         "the numbers is proportional to their numeric values. " +
         "For example, \nnumbers are generated in the " +
         "vicinity of 0.75 with three times the \n" +
         "probability of those generated near 0.25.");
      Console::WriteLine(
         "\nRandom doubles generated with the NextDouble() " +
         "method:\n");

      // Generate and display [rows * cols] random doubles.
      for (int i = 0; i < rows; i++)
      {
         for (int j = 0; j < cols; j++) 
               Console::Write("{0,12:F8}", randObj->NextDouble());
         Console::WriteLine();
      }

      Console::WriteLine(
         "\nRandom integers generated with the Next() " +
         "method:\n");

      // Generate and display [rows * cols] random integers.
      for (int i = 0; i < rows; i++)
      {
         for (int j = 0; j < cols; j++)
               Console::Write("{0,12}", randObj->Next());
         Console::WriteLine();
      }

      Console::WriteLine(
         "\nTo demonstrate the proportional distribution, " +
         "{0:N0} random \nintegers and doubles are grouped " +
         "into {1} equal value ranges. This \n" +
         "is the count of values in each range:\n",
         runCount, distGroupCount);
      Console::WriteLine(
         "{0,21}{1,10}{2,20}{3,10}", "Integer Range",
         "Count", "Double Range", "Count");
      Console::WriteLine(
         "{0,21}{1,10}{2,20}{3,10}", "-------------",
         "-----", "------------", "-----");

      // Generate random integers and doubles, and then count 
      // them by group.
      for (int i = 0; i < runCount; i++)
      {
         intCounts[ (int)((double)randObj->Next() / 
               intGroupSize) ]++;
         realCounts[ (int)(randObj->NextDouble() * 
               (double)distGroupCount) ]++;
      }

      // Display the count of each group.
      for (int i = 0; i < distGroupCount; i++)
         Console::WriteLine(
               "{0,10}-{1,10}{2,10:N0}{3,12:N5}-{4,7:N5}{5,10:N0}",
               (int)((double)i * intGroupSize),
               (int)((double)(i + 1) * intGroupSize - 1.0),
               intCounts[ i ],
               ((double)i) / (double)distGroupCount,
               ((double)(i + 1)) / (double)distGroupCount,
               realCounts[ i ]);
      return 0;
}

/*
This example of Random.Sample() displays output similar to the following:

   The derived RandomProportional class overrides the Sample method to
   generate random numbers in the range [0.0, 1.0). The distribution
   of the numbers is proportional to the number values. For example,
   numbers are generated in the vicinity of 0.75 with three times the
   probability of those generated near 0.25.

   Random doubles generated with the NextDouble() method:

     0.59455719  0.17589882  0.83134398  0.35795862  0.91467727  0.54022658
     0.93716947  0.54817519  0.94685080  0.93705478  0.18582318  0.71272428
     0.77708682  0.95386216  0.70412393  0.86099417  0.08275804  0.79108316
     0.71019941  0.84205103  0.41685082  0.58186880  0.89492302  0.73067715

   Random integers generated with the Next() method:

     1570755704  1279192549  1747627711  1705700211  1372759203  1849655615
     2046235980  1210843924  1554274149  1307936697  1480207570  1057595022
      337854215   844109928  2028310798  1386669369  2073517658  1291729809
     1537248240  1454198019  1934863511  1640004334  2032620207   534654791

   To demonstrate the proportional distribution, 1,000,000 random
   integers and doubles are grouped into 10 equal value ranges. This
   is the count of values in each range:

           Integer Range     Count        Double Range     Count
           -------------     -----        ------------     -----
            0- 214748363    10,079     0.00000-0.10000    10,148
    214748364- 429496728    29,835     0.10000-0.20000    29,849
    429496729- 644245093    49,753     0.20000-0.30000    49,948
    644245094- 858993458    70,325     0.30000-0.40000    69,656
    858993459-1073741823    89,906     0.40000-0.50000    90,337
   1073741824-1288490187   109,868     0.50000-0.60000   110,225
   1288490188-1503238552   130,388     0.60000-0.70000   129,986
   1503238553-1717986917   149,231     0.70000-0.80000   150,428
   1717986918-1932735282   170,234     0.80000-0.90000   169,610
   1932735283-2147483647   190,381     0.90000-1.00000   189,813
*/
using System;

// This derived class converts the uniformly distributed random
// numbers generated by base.Sample() to another distribution.
public class RandomProportional : Random
{
    // The Sample method generates a distribution proportional to the value
    // of the random numbers, in the range [0.0, 1.0].
    protected override double Sample()
    {
        return Math.Sqrt(base.Sample());
    }

    public override int Next()
    {
       return (int) (Sample() * int.MaxValue);
    }
}

public class RandomSampleDemo
{
    static void Main()
    {	
        const int rows = 4, cols = 6;
        const int runCount = 1000000;
        const int distGroupCount = 10;
        const double intGroupSize =
            ((double)int.MaxValue + 1.0) / (double)distGroupCount;

        RandomProportional randObj = new RandomProportional();

        int[ ]      intCounts = new int[ distGroupCount ];
        int[ ]      realCounts = new int[ distGroupCount ];

        Console.WriteLine(
            "\nThe derived RandomProportional class overrides " +
            "the Sample method to \ngenerate random numbers " +
            "in the range [0.0, 1.0]. The distribution \nof " +
            "the numbers is proportional to their numeric values. " +
            "For example, \nnumbers are generated in the " +
            "vicinity of 0.75 with three times the \n" +
            "probability of those generated near 0.25.");
        Console.WriteLine(
            "\nRandom doubles generated with the NextDouble() " +
            "method:\n");

        // Generate and display [rows * cols] random doubles.
        for (int i = 0; i < rows; i++)
        {
            for (int j = 0; j < cols; j++)
                Console.Write("{0,12:F8}", randObj.NextDouble());
            Console.WriteLine();
        }

        Console.WriteLine(
            "\nRandom integers generated with the Next() " +
            "method:\n");

        // Generate and display [rows * cols] random integers.
        for (int i = 0; i < rows; i++)
        {
            for (int j = 0; j < cols; j++)
                Console.Write("{0,12}", randObj.Next());
            Console.WriteLine();
        }

        Console.WriteLine(
            "\nTo demonstrate the proportional distribution, " +
            "{0:N0} random \nintegers and doubles are grouped " +
            "into {1} equal value ranges. This \n" +
            "is the count of values in each range:\n",
            runCount, distGroupCount);
        Console.WriteLine(
            "{0,21}{1,10}{2,20}{3,10}", "Integer Range",
            "Count", "Double Range", "Count");
        Console.WriteLine(
            "{0,21}{1,10}{2,20}{3,10}", "-------------",
            "-----", "------------", "-----");

        // Generate random integers and doubles, and then count
        // them by group.
        for (int i = 0; i < runCount; i++)
        {
            intCounts[ (int)((double)randObj.Next() /
                intGroupSize) ]++;
            realCounts[ (int)(randObj.NextDouble() *
                (double)distGroupCount) ]++;
        }

        // Display the count of each group.
        for (int i = 0; i < distGroupCount; i++)
            Console.WriteLine(
                "{0,10}-{1,10}{2,10:N0}{3,12:N5}-{4,7:N5}{5,10:N0}",
                (int)((double)i * intGroupSize),
                (int)((double)(i + 1) * intGroupSize - 1.0),
                intCounts[ i ],
                ((double)i) / (double)distGroupCount,
                ((double)(i + 1)) / (double)distGroupCount,
                realCounts[ i ]);
    }
}

/*
This example of Random.Sample() displays output similar to the following:

   The derived RandomProportional class overrides the Sample method to
   generate random numbers in the range [0.0, 1.0). The distribution
   of the numbers is proportional to the number values. For example,
   numbers are generated in the vicinity of 0.75 with three times the
   probability of those generated near 0.25.

   Random doubles generated with the NextDouble() method:

     0.59455719  0.17589882  0.83134398  0.35795862  0.91467727  0.54022658
     0.93716947  0.54817519  0.94685080  0.93705478  0.18582318  0.71272428
     0.77708682  0.95386216  0.70412393  0.86099417  0.08275804  0.79108316
     0.71019941  0.84205103  0.41685082  0.58186880  0.89492302  0.73067715

   Random integers generated with the Next() method:

     1570755704  1279192549  1747627711  1705700211  1372759203  1849655615
     2046235980  1210843924  1554274149  1307936697  1480207570  1057595022
      337854215   844109928  2028310798  1386669369  2073517658  1291729809
     1537248240  1454198019  1934863511  1640004334  2032620207   534654791

   To demonstrate the proportional distribution, 1,000,000 random
   integers and doubles are grouped into 10 equal value ranges. This
   is the count of values in each range:

           Integer Range     Count        Double Range     Count
           -------------     -----        ------------     -----
            0- 214748363    10,079     0.00000-0.10000    10,148
    214748364- 429496728    29,835     0.10000-0.20000    29,849
    429496729- 644245093    49,753     0.20000-0.30000    49,948
    644245094- 858993458    70,325     0.30000-0.40000    69,656
    858993459-1073741823    89,906     0.40000-0.50000    90,337
   1073741824-1288490187   109,868     0.50000-0.60000   110,225
   1288490188-1503238552   130,388     0.60000-0.70000   129,986
   1503238553-1717986917   149,231     0.70000-0.80000   150,428
   1717986918-1932735282   170,234     0.80000-0.90000   169,610
   1932735283-2147483647   190,381     0.90000-1.00000   189,813
*/
' This derived class converts the uniformly distributed random 
' numbers generated by base.Sample() to another distribution.
Public Class RandomProportional
   Inherits Random

   ' The Sample method generates a distribution proportional to the value 
   ' of the random numbers, in the range [0.0, 1.0].
   Protected Overrides Function Sample() As Double
      Return Math.Sqrt(MyBase.Sample())
   End Function
   
   Public Overrides Function [Next]() As Integer
      Return Sample() * Integer.MaxValue
   End Function 
End Class 

Module RandomSampleDemo
    Sub Main()
        Const rows As Integer = 4, cols As Integer = 6
        Const runCount As Integer = 1000000
        Const distGroupCount As Integer = 10
        Const intGroupSize As Double = _
            (CDbl(Integer.MaxValue) + 1.0) / _
            CDbl(distGroupCount)
            
        Dim randObj As New RandomProportional()
            
        Dim intCounts(distGroupCount) As Integer
        Dim realCounts(distGroupCount) As Integer
        Dim i As Integer, j As Integer 
            
        Console.WriteLine(vbCrLf & _
            "The derived RandomProportional class overrides " & _ 
            "the Sample method to " & vbCrLf & _
            "generate random numbers in the range " & _ 
            "[0.0, 1.0]. The distribution " & vbCrLf & _
            "of the numbers is proportional to their numeric " & _
            "values. For example, " & vbCrLf & _ 
            "numbers are generated in the vicinity of 0.75 " & _
            "with three times " & vbCrLf & "the " & _
            "probability of those generated near 0.25.")
        Console.WriteLine(vbCrLf & _
            "Random doubles generated with the NextDouble() " & _ 
            "method:" & vbCrLf)
            
        ' Generate and display [rows * cols] random doubles.
        For i = 0 To rows - 1
            For j = 0 To cols - 1
                Console.Write("{0,12:F8}", randObj.NextDouble())
            Next j
            Console.WriteLine()
        Next i
            
        Console.WriteLine(vbCrLf & _
            "Random integers generated with the Next() " & _ 
            "method:" & vbCrLf)
            
        ' Generate and display [rows * cols] random integers.
        For i = 0 To rows - 1
            For j = 0 To cols - 1
                Console.Write("{0,12}", randObj.Next())
            Next j
            Console.WriteLine()
        Next i
            
        Console.WriteLine(vbCrLf & _
            "To demonstrate the proportional distribution, " & _ 
            "{0:N0} random " & vbCrLf & _
            "integers and doubles are grouped into {1} " & _ 
            "equal value ranges. This " & vbCrLf & _
            "is the count of values in each range:" & vbCrLf, _
            runCount, distGroupCount)
        Console.WriteLine("{0,21}{1,10}{2,20}{3,10}", _
            "Integer Range", "Count", "Double Range", "Count")
        Console.WriteLine("{0,21}{1,10}{2,20}{3,10}", _
            "-------------", "-----", "------------", "-----")
            
        ' Generate random integers and doubles, and then count 
        ' them by group.
        For i = 0 To runCount - 1
            intCounts(Fix(CDbl(randObj.Next()) / _
                intGroupSize)) += 1
            realCounts(Fix(randObj.NextDouble() * _
                CDbl(distGroupCount))) += 1
        Next i
            
        ' Display the count of each group.
        For i = 0 To distGroupCount - 1
            Console.WriteLine( _
                "{0,10}-{1,10}{2,10:N0}{3,12:N5}-{4,7:N5}{5,10:N0}", _
                Fix(CDbl(i) * intGroupSize), _
                Fix(CDbl(i + 1) * intGroupSize - 1.0), _
                intCounts(i), _
                CDbl(i) / CDbl(distGroupCount), _
                CDbl(i + 1) / CDbl(distGroupCount), _
                realCounts(i))
        Next i
    End Sub
End Module 
' This example of Random.Sample() generates output similar to the following:
'
'    The derived RandomProportional class overrides the Sample method to
'    generate random numbers in the range [0.0, 1.0]. The distribution
'    of the numbers is proportional to their numeric values. For example,
'    numbers are generated in the vicinity of 0.75 with three times
'    the probability of those generated near 0.25.
'    
'    Random doubles generated with the NextDouble() method:
'    
'      0.28377004  0.75920598  0.33430371  0.66720626  0.97080243  0.27353772
'      0.17787962  0.54618410  0.08145080  0.56286100  0.99002910  0.64898614
'      0.27673277  0.99455281  0.93778966  0.76162002  0.70533771  0.44375798
'      0.55939883  0.87383136  0.66465779  0.77392566  0.42393411  0.82409159
'    
'    Random integers generated with the Next() method:
'    
'      1364479914  1230312341  1657373812  1526222928   988564704   700078020
'      1801013705  1541517421  1146312560   338318389  1558995993  2027260859
'       884520932  1320070465   570200106  1027684711   943035246  2088689333
'       630809089  1705728475  2140787648  2097858166  1863010875  1386804198
'    
'    To demonstrate the proportional distribution, 1,000,000 random
'    integers and doubles are grouped into 10 equal value ranges. This
'    is the count of values in each range:
'    
'            Integer Range     Count        Double Range     Count
'            -------------     -----        ------------     -----
'             0- 214748363     9,892     0.00000-0.10000     9,928
'     214748364- 429496728    30,341     0.10000-0.20000    30,101
'     429496729- 644245093    49,958     0.20000-0.30000    49,964
'     644245094- 858993458    70,099     0.30000-0.40000    70,213
'     858993459-1073741823    90,801     0.40000-0.50000    89,553
'    1073741824-1288490187   109,699     0.50000-0.60000   109,427
'    1288490188-1503238552   129,438     0.60000-0.70000   130,339
'    1503238553-1717986917   149,886     0.70000-0.80000   150,000
'    1717986918-1932735282   170,338     0.80000-0.90000   170,128
'    1932735283-2147483647   189,548     0.90000-1.00000   190,347

注解

Random.Next 生成值范围从0到小于的随机数 Int32.MaxValue 。 若要生成其值范围从0到其他正数的随机数字,请使用 Random.Next(Int32) 方法重载。 若要在不同的范围内生成随机数字,请使用 Random.Next(Int32, Int32) 方法重载。

继承者说明

从 .NET Framework 版本2.0 开始,如果从派生类 Random 并重写 Sample() 方法,则 Sample() 不会在调用方法的基类实现时使用方法的派生类实现提供的分布 Next() 。 相反,将使用基类返回的统一分布 Random 。 此行为可改善类的整体性能 Random 。 若要修改此行为以调用 Sample() 派生类中的方法,还必须重写 Next() 方法。

另请参阅

适用于

Next(Int32)

返回一个小于所指定最大值的非负随机整数。

public:
 virtual int Next(int maxValue);
public virtual int Next (int maxValue);
abstract member Next : int -> int
override this.Next : int -> int
Public Overridable Function Next (maxValue As Integer) As Integer

参数

maxValue
Int32

要生成的随机数的上限(随机数不能取该上限值)。 maxValue 必须大于或等于 0。

返回

Int32

大于或等于零且小于 maxValue 的 32 位有符号整数,即:返回值的范围通常包括零但不包括 maxValue。 但是,如果 maxValue 等于 0,则返回 maxValue

例外

maxValue 小于 0。

示例

下面的示例生成包含方法的各种重载的随机整数 Next

// Example of the Random::Next() methods.
using namespace System;

// Generate random numbers with no bounds specified.
void NoBoundsRandoms(int seed)
{
   Console::WriteLine("\nRandom object, seed = {0}, no bounds:", seed);
   Random^ randObj = gcnew Random(seed);
   
   // Generate six random integers from 0 to int.MaxValue.
   for (int j = 0; j < 6; j++)
      Console::Write("{0,11} ", randObj->Next());
   Console::WriteLine();
}


// Generate random numbers with an upper bound specified.
void UpperBoundRandoms(int seed, int upper)
{
   Console::WriteLine("\nRandom object, seed = {0}, upper bound = {1}:", seed, upper);
   Random^ randObj = gcnew Random(seed);
   
   // Generate six random integers from 0 to the upper bound.
   for (int j = 0; j < 6; j++)
      Console::Write("{0,11} ", randObj->Next(upper));
   Console::WriteLine();
}


// Generate random numbers with both bounds specified.
void BothBoundsRandoms(int seed, int lower, int upper)
{
   Console::WriteLine("\nRandom object, seed = {0}, lower = {1}, upper = {2}:", seed, lower, upper);
   Random^ randObj = gcnew Random(seed);
   
   // Generate six random integers from the lower to 
   // upper bounds.
   for (int j = 0; j < 6; j++)
      Console::Write("{0,11} ", randObj->Next(lower, upper));
   Console::WriteLine();
}

int main()
{
   Console::WriteLine("This example of the Random::Next() methods\n"
   "generates the following output.\n");
   Console::WriteLine("Create Random objects all with the same seed and "
   "generate\nsequences of numbers with different "
   "bounds. Note the effect\nthat the various "
   "combinations of bounds have on the sequences.");
   NoBoundsRandoms(234);
   UpperBoundRandoms(234, Int32::MaxValue);
   UpperBoundRandoms(234, 2000000000);
   UpperBoundRandoms(234, 200000000);
   BothBoundsRandoms(234, 0, Int32::MaxValue);
   BothBoundsRandoms(234, Int32::MinValue, Int32::MaxValue);
   BothBoundsRandoms(234, -2000000000, 2000000000);
   BothBoundsRandoms(234, -200000000, 200000000);
   BothBoundsRandoms(234, -2000, 2000);
}

/*
This example of the Random::Next() methods
generates the following output.

Create Random objects all with the same seed and generate
sequences of numbers with different bounds. Note the effect
that the various combinations of bounds have on the sequences.

Random object, seed = 234, no bounds:
 2091148258  1024955023   711273344  1081917183  1833298756   109460588

Random object, seed = 234, upper bound = 2147483647:
 2091148258  1024955023   711273344  1081917183  1833298756   109460588

Random object, seed = 234, upper bound = 2000000000:
 1947533580   954563751   662424922  1007613896  1707392518   101943116

Random object, seed = 234, upper bound = 200000000:
  194753358    95456375    66242492   100761389   170739251    10194311

Random object, seed = 234, lower = 0, upper = 2147483647:
 2091148258  1024955023   711273344  1081917183  1833298756   109460588

Random object, seed = 234, lower = -2147483648, upper = 2147483647:
 2034812868   -97573602  -724936960    16350718  1519113864 -1928562472

Random object, seed = 234, lower = -2000000000, upper = 2000000000:
 1895067160   -90872498  -675150156    15227793  1414785036 -1796113767

Random object, seed = 234, lower = -200000000, upper = 200000000:
  189506716    -9087250   -67515016     1522779   141478503  -179611377

Random object, seed = 234, lower = -2000, upper = 2000:
       1895         -91        -676          15        1414       -1797
*/
Console.WriteLine(
    "This example of the Random.Next() methods\n" +
    "generates the following output.\n");
Console.WriteLine(
    "Create Random objects all with the same seed and " +
    "generate\nsequences of numbers with different " +
    "bounds. Note the effect\nthat the various " +
    "combinations of bounds have on the sequences.");

NoBoundsRandoms(234);

UpperBoundRandoms(234, Int32.MaxValue);
UpperBoundRandoms(234, 2000000000);
UpperBoundRandoms(234, 200000000);

BothBoundsRandoms(234, 0, Int32.MaxValue);
BothBoundsRandoms(234, Int32.MinValue, Int32.MaxValue);
BothBoundsRandoms(234, -2000000000, 2000000000);
BothBoundsRandoms(234, -200000000, 200000000);
BothBoundsRandoms(234, -2000, 2000);

// Generate random numbers with no bounds specified.
void NoBoundsRandoms(int seed)
{
    Console.WriteLine(
        "\nRandom object, seed = {0}, no bounds:", seed);
    Random randObj = new Random(seed);

    // Generate six random integers from 0 to int.MaxValue.
    for (int j = 0; j < 6; j++)
        Console.Write("{0,11} ", randObj.Next());
    Console.WriteLine();
}

// Generate random numbers with an upper bound specified.
void UpperBoundRandoms(int seed, int upper)
{
    Console.WriteLine(
        "\nRandom object, seed = {0}, upper bound = {1}:",
        seed, upper);
    Random randObj = new Random(seed);

    // Generate six random integers from 0 to the upper bound.
    for (int j = 0; j < 6; j++)
        Console.Write("{0,11} ", randObj.Next(upper));
    Console.WriteLine();
}

// Generate random numbers with both bounds specified.
void BothBoundsRandoms(int seed, int lower, int upper)
{
    Console.WriteLine(
        "\nRandom object, seed = {0}, lower = {1}, " +
        "upper = {2}:", seed, lower, upper);
    Random randObj = new Random(seed);

    // Generate six random integers from the lower to
    // upper bounds.
    for (int j = 0; j < 6; j++)
        Console.Write("{0,11} ",
            randObj.Next(lower, upper));
    Console.WriteLine();
}

/*
This example of the Random.Next() methods
generates the following output.

Create Random objects all with the same seed and generate
sequences of numbers with different bounds. Note the effect
that the various combinations of bounds have on the sequences.

Random object, seed = 234, no bounds:
2091148258  1024955023   711273344  1081917183  1833298756   109460588

Random object, seed = 234, upper bound = 2147483647:
2091148258  1024955023   711273344  1081917183  1833298756   109460588

Random object, seed = 234, upper bound = 2000000000:
1947533580   954563751   662424922  1007613896  1707392518   101943116

Random object, seed = 234, upper bound = 200000000:
194753358    95456375    66242492   100761389   170739251    10194311

Random object, seed = 234, lower = 0, upper = 2147483647:
2091148258  1024955023   711273344  1081917183  1833298756   109460588

Random object, seed = 234, lower = -2147483648, upper = 2147483647:
2034812868   -97573602  -724936960    16350718  1519113864 -1928562472

Random object, seed = 234, lower = -2000000000, upper = 2000000000:
1895067160   -90872498  -675150156    15227793  1414785036 -1796113767

Random object, seed = 234, lower = -200000000, upper = 200000000:
189506716    -9087250   -67515016     1522779   141478503  -179611377

Random object, seed = 234, lower = -2000, upper = 2000:
    1895         -91        -676          15        1414       -1797
*/
let noBoundsRandoms seed =
    printfn "\nRandom object, seed = %i, no bounds:" seed
    let randObj = Random seed

    // Generate six random integers from 0 to int.MaxValue.
    for _ = 1 to 6 do
        printf $"%11i{randObj.Next()} "
    printfn ""

// Generate random numbers with an upper bound specified.
let upperBoundRandoms seed upper = 
    printfn $"\nRandom object, seed = %i{seed}, upper bound = %i{upper}"
    let randObj = Random seed

    // Generate six random integers from 0 to the upper bound.
    for _ = 1 to 6 do
        printf $"%11i{randObj.Next upper} "
    printfn ""

// Generate random numbers with both bounds specified.
let bothBoundRandoms seed lower upper =
    printfn $"\nRandom object, seed = %i{seed}, lower = %i{lower}, upper = %i{upper}: "
    let randObj = Random seed

    // Generate six random integers from the lower to upper bounds.
    for _ = 1 to 6 do 
        printf $"%11i{randObj.Next(lower,upper)} "
    printfn ""

printfn "This example of the Random.Next() methods\ngenerates the following.\n"

printfn """Create Random objects all with the same seed and generate
sequences of numbers with different bounds. Note the effect
that the various combinations of bounds have on the sequences."""

noBoundsRandoms 234

upperBoundRandoms 234 Int32.MaxValue
upperBoundRandoms 234 2000000000
upperBoundRandoms 234 200000000

bothBoundRandoms 234 0 Int32.MaxValue
bothBoundRandoms 234 Int32.MinValue Int32.MaxValue
bothBoundRandoms 234 -2000000000 2000000000
bothBoundRandoms 234 -200000000 200000000
bothBoundRandoms 234 -2000 2000

(*
This example of the Random.Next() methods
generates the following output.

Create Random objects all with the same seed and generate
sequences of numbers with different bounds. Note the effect
that the various combinations of bounds have on the sequences.

Random object, seed = 234, no bounds:
2091148258  1024955023   711273344  1081917183  1833298756   109460588

Random object, seed = 234, upper bound = 2147483647:
2091148258  1024955023   711273344  1081917183  1833298756   109460588

Random object, seed = 234, upper bound = 2000000000:
1947533580   954563751   662424922  1007613896  1707392518   101943116

Random object, seed = 234, upper bound = 200000000:
194753358    95456375    66242492   100761389   170739251    10194311

Random object, seed = 234, lower = 0, upper = 2147483647:
2091148258  1024955023   711273344  1081917183  1833298756   109460588

Random object, seed = 234, lower = -2147483648, upper = 2147483647:
2034812868   -97573602  -724936960    16350718  1519113864 -1928562472

Random object, seed = 234, lower = -2000000000, upper = 2000000000:
1895067160   -90872498  -675150156    15227793  1414785036 -1796113767

Random object, seed = 234, lower = -200000000, upper = 200000000:
189506716    -9087250   -67515016     1522779   141478503  -179611377

Random object, seed = 234, lower = -2000, upper = 2000:
    1895         -91        -676          15        1414       -1797
*)
' Example of the Random.Next() methods.
Module RandomNextDemo

    ' Generate random numbers with no bounds specified.
    Sub NoBoundsRandoms(seed As Integer)

        Console.WriteLine(vbCrLf &
            "Random object, seed = {0}, no bounds:", seed)
        Dim randObj As New Random(seed)

        ' Generate six random integers from 0 to int.MaxValue.
        Dim j As Integer
        For j = 0 To 5
            Console.Write("{0,11} ", randObj.Next())
        Next j
        Console.WriteLine()
    End Sub

    ' Generate random numbers with an upper bound specified.
    Sub UpperBoundRandoms(seed As Integer, upper As Integer)

        Console.WriteLine(vbCrLf &
            "Random object, seed = {0}, upper bound = {1}:",
            seed, upper)
        Dim randObj As New Random(seed)

        ' Generate six random integers from 0 to the upper bound.
        Dim j As Integer
        For j = 0 To 5
            Console.Write("{0,11} ", randObj.Next(upper))
        Next j
        Console.WriteLine()
    End Sub

    ' Generate random numbers with both bounds specified.
    Sub BothBoundsRandoms(seed As Integer, lower As Integer, upper As Integer)

        Console.WriteLine(vbCrLf &
            "Random object, seed = {0}, lower = {1}, " &
            "upper = {2}:", seed, lower, upper)
        Dim randObj As New Random(seed)

        ' Generate six random integers from the lower to 
        ' upper bounds.
        Dim j As Integer
        For j = 0 To 5
            Console.Write("{0,11} ",
                randObj.Next(lower, upper))
        Next j
        Console.WriteLine()
    End Sub

    Sub Main()
        Console.WriteLine(
            "This example of the Random.Next() methods" &
            vbCrLf & "generates the following output." & vbCrLf)
        Console.WriteLine(
            "Create Random objects all with the same seed " &
            "and generate" & vbCrLf & "sequences of numbers " &
            "with different bounds. Note the effect " & vbCrLf &
            "that the various combinations " &
            "of bounds have on the sequences.")

        NoBoundsRandoms(234)

        UpperBoundRandoms(234, Int32.MaxValue)
        UpperBoundRandoms(234, 2000000000)
        UpperBoundRandoms(234, 200000000)

        BothBoundsRandoms(234, 0, Int32.MaxValue)
        BothBoundsRandoms(234, Int32.MinValue, Int32.MaxValue)
        BothBoundsRandoms(234, -2000000000, 2000000000)
        BothBoundsRandoms(234, -200000000, 200000000)
        BothBoundsRandoms(234, -2000, 2000)
    End Sub
End Module

' This example of the Random.Next() methods
' generates the following output.
' 
' Create Random objects all with the same seed and generate
' sequences of numbers with different bounds. Note the effect
' that the various combinations of bounds have on the sequences.
' 
' Random object, seed = 234, no bounds:
'  2091148258  1024955023   711273344  1081917183  1833298756   109460588
' 
' Random object, seed = 234, upper bound = 2147483647:
'  2091148258  1024955023   711273344  1081917183  1833298756   109460588
' 
' Random object, seed = 234, upper bound = 2000000000:
'  1947533580   954563751   662424922  1007613896  1707392518   101943116
' 
' Random object, seed = 234, upper bound = 200000000:
'   194753358    95456375    66242492   100761389   170739251    10194311
' 
' Random object, seed = 234, lower = 0, upper = 2147483647:
'  2091148258  1024955023   711273344  1081917183  1833298756   109460588
' 
' Random object, seed = 234, lower = -2147483648, upper = 2147483647:
'  2034812868   -97573602  -724936960    16350718  1519113864 -1928562472
' 
' Random object, seed = 234, lower = -2000000000, upper = 2000000000:
'  1895067160   -90872498  -675150156    15227793  1414785036 -1796113767
' 
' Random object, seed = 234, lower = -200000000, upper = 200000000:
'   189506716    -9087250   -67515016     1522779   141478503  -179611377
' 
' Random object, seed = 234, lower = -2000, upper = 2000:
'        1895         -91        -676          15        1414       -1797

下面的示例生成一个随机整数,该整数将用作索引以检索数组中的字符串值。 由于数组的最高索引小于其长度,因此该属性的值 Array.Length 作为 maxValue 参数提供。

using namespace System;

void main()
{
   Random^ rnd = gcnew Random();
   array<String^>^ malePetNames = { "Rufus", "Bear", "Dakota", "Fido",
                                    "Vanya", "Samuel", "Koani", "Volodya",
                                    "Prince", "Yiska" };
   array<String^>^ femalePetNames = { "Maggie", "Penny", "Saya", "Princess",
                                      "Abby", "Laila", "Sadie", "Olivia",
                                      "Starlight", "Talla" };
      
   // Generate random indexes for pet names.
   int mIndex = rnd->Next(malePetNames->Length);
   int fIndex = rnd->Next(femalePetNames->Length);
      
   // Display the result.
   Console::WriteLine("Suggested pet name of the day: ");
   Console::WriteLine("   For a male:     {0}", malePetNames[mIndex]);
   Console::WriteLine("   For a female:   {0}", femalePetNames[fIndex]);
}
// The example displays output similar to the following:
//       Suggested pet name of the day:
//          For a male:     Koani
//          For a female:   Maggie
Random rnd = new Random();
string[] malePetNames = { "Rufus", "Bear", "Dakota", "Fido",
                          "Vanya", "Samuel", "Koani", "Volodya",
                          "Prince", "Yiska" };
string[] femalePetNames = { "Maggie", "Penny", "Saya", "Princess",
                            "Abby", "Laila", "Sadie", "Olivia",
                            "Starlight", "Talla" };

// Generate random indexes for pet names.
int mIndex = rnd.Next(malePetNames.Length);
int fIndex = rnd.Next(femalePetNames.Length);

// Display the result.
Console.WriteLine("Suggested pet name of the day: ");
Console.WriteLine("   For a male:     {0}", malePetNames[mIndex]);
Console.WriteLine("   For a female:   {0}", femalePetNames[fIndex]);

// The example displays output similar to the following:
//       Suggested pet name of the day:
//          For a male:     Koani
//          For a female:   Maggie
let rnd = Random()

let malePetNames =
    [| "Rufus"; "Bear"; "Dakota"; "Fido";
        "Vanya"; "Samuel"; "Koani"; "Volodya";
        "Prince"; "Yiska" |]
let femalePetNames = 
    [| "Maggie"; "Penny"; "Saya"; "Princess";
        "Abby"; "Laila"; "Sadie"; "Olivia";
        "Starlight"; "Talla" |]

// Generate random indexes for pet names.
let mIndex = rnd.Next malePetNames.Length
let fIndex = rnd.Next femalePetNames.Length

// Display the result.
printfn "Suggested pet name of the day: "
printfn "   For a male:     %s" malePetNames.[mIndex]
printfn "   For a female:   %s" femalePetNames.[fIndex]

// The example displays output similar to the following:
//       Suggested pet name of the day:
//          For a male:     Koani
//          For a female:   Maggie
Module Example
   Public Sub Main()
      Dim rnd As New Random()
      Dim malePetNames() As String = { "Rufus", "Bear", "Dakota", "Fido", 
                                    "Vanya", "Samuel", "Koani", "Volodya", 
                                    "Prince", "Yiska" }
      Dim femalePetNames() As String = { "Maggie", "Penny", "Saya", "Princess", 
                                         "Abby", "Laila", "Sadie", "Olivia", 
                                         "Starlight", "Talla" }                                      
      
      ' Generate random indexes for pet names.
      Dim mIndex As Integer = rnd.Next(malePetNames.Length)
      Dim fIndex As Integer = rnd.Next(femalePetNames.Length)
      
      ' Display the result.
      Console.WriteLine("Suggested pet name of the day: ")
      Console.WriteLine("   For a male:     {0}", malePetNames(mIndex))
      Console.WriteLine("   For a female:   {0}", femalePetNames(fIndex))
   End Sub
End Module
' The example displays output similar to the following:
'       Suggested pet name of the day:
'          For a male:     Koani
'          For a female:   Maggie

注解

Next(Int32)重载返回介于0到-1 之间的随机整数 maxValue 。 但是,如果 maxValue 为0,则该方法返回0。

另请参阅

适用于

Next(Int32, Int32)

返回在指定范围内的任意整数。

public:
 virtual int Next(int minValue, int maxValue);
public virtual int Next (int minValue, int maxValue);
abstract member Next : int * int -> int
override this.Next : int * int -> int
Public Overridable Function Next (minValue As Integer, maxValue As Integer) As Integer

参数

minValue
Int32

返回的随机数的下界(随机数可取该下界值)。

maxValue
Int32

返回的随机数的上界(随机数不能取该上界值)。 maxValue 必须大于或等于 minValue

返回

Int32

一个大于等于 minValue 且小于 maxValue 的 32 位带符号整数,即:返回的值范围包括 minValue 但不包括 maxValue。 如果 minValue 等于 maxValue,则返回 minValue

例外

minValue 大于 maxValue

示例

下面的示例使用 Random.Next(Int32, Int32) 方法生成具有三个不同范围的随机整数。 请注意,该示例的确切输出取决于传递给类构造函数的系统提供的种子值 Random

using namespace System;

void main()
{
   Random^ rnd = gcnew Random();

   Console::WriteLine("\n20 random integers from -100 to 100:");
   for (int ctr = 1; ctr <= 20; ctr++) 
   {
      Console::Write("{0,6}", rnd->Next(-100, 101));
      if (ctr % 5 == 0) Console::WriteLine();
   }
   
   Console::WriteLine("\n20 random integers from 1000 to 10000:");      
   for (int ctr = 1; ctr <= 20; ctr++) 
   {
      Console::Write("{0,8}", rnd->Next(1000, 10001));
      if (ctr % 5 == 0) Console::WriteLine();
   }
   
   Console::WriteLine("\n20 random integers from 1 to 10:");
   for (int ctr = 1; ctr <= 20; ctr++) 
   {
      Console::Write("{0,6}", rnd->Next(1, 11));
      if (ctr % 5 == 0) Console::WriteLine();
   }
}
// The example displays output similar to the following:
//       20 random integers from -100 to 100:
//           65   -95   -10    90   -35
//          -83   -16   -15   -19    41
//          -67   -93    40    12    62
//          -80   -95    67   -81   -21
//       
//       20 random integers from 1000 to 10000:
//           4857    9897    4405    6606    1277
//           9238    9113    5151    8710    1187
//           2728    9746    1719    3837    3736
//           8191    6819    4923    2416    3028
//       
//       20 random integers from 1 to 10:
//            9     8     5     9     9
//            9     1     2     3     8
//            1     4     8    10     5
//            9     7     9    10     5
Random rnd = new Random();

Console.WriteLine("\n20 random integers from -100 to 100:");
for (int ctr = 1; ctr <= 20; ctr++)
{
   Console.Write("{0,6}", rnd.Next(-100, 101));
   if (ctr % 5 == 0) Console.WriteLine();
}

Console.WriteLine("\n20 random integers from 1000 to 10000:");
for (int ctr = 1; ctr <= 20; ctr++)
{
   Console.Write("{0,8}", rnd.Next(1000, 10001));
   if (ctr % 5 == 0) Console.WriteLine();
}

Console.WriteLine("\n20 random integers from 1 to 10:");
for (int ctr = 1; ctr <= 20; ctr++)
{
   Console.Write("{0,6}", rnd.Next(1, 11));
   if (ctr % 5 == 0) Console.WriteLine();
}

// The example displays output similar to the following:
//       20 random integers from -100 to 100:
//           65   -95   -10    90   -35
//          -83   -16   -15   -19    41
//          -67   -93    40    12    62
//          -80   -95    67   -81   -21
//
//       20 random integers from 1000 to 10000:
//           4857    9897    4405    6606    1277
//           9238    9113    5151    8710    1187
//           2728    9746    1719    3837    3736
//           8191    6819    4923    2416    3028
//
//       20 random integers from 1 to 10:
//            9     8     5     9     9
//            9     1     2     3     8
//            1     4     8    10     5
//            9     7     9    10     5
let rnd = Random()

printfn "\n20 random integers from -100 to 100:"
for i = 1 to 20 do 
    printf "%6i" (rnd.Next(-100,100))
    if i % 5 = 0 then printfn ""

printfn "\n20 random integers from 1000 to 10000:"
for i = 1 to 20 do 
    printf "%8i" (rnd.Next(1000,10001))
    if i % 5 = 0 then printfn ""

printfn "\n20 random integers from 1 to 10:"
for i = 1 to 20 do 
    printf "%6i" (rnd.Next(1,11))
    if i % 5 = 0 then printfn ""

// The example displays output similar to the following:
//       20 random integers from -100 to 100:
//           65   -95   -10    90   -35
//          -83   -16   -15   -19    41
//          -67   -93    40    12    62
//          -80   -95    67   -81   -21
//
//       20 random integers from 1000 to 10000:
//           4857    9897    4405    6606    1277
//           9238    9113    5151    8710    1187
//           2728    9746    1719    3837    3736
//           8191    6819    4923    2416    3028
//
//       20 random integers from 1 to 10:
//            9     8     5     9     9
//            9     1     2     3     8
//            1     4     8    10     5
//            9     7     9    10     5
Module Example
   Public Sub Main()
      Dim rnd As New Random()

      Console.WriteLine("20 random integers from -100 to 100:")
      For ctr As Integer = 1 To 20
         Console.Write("{0,6}", rnd.Next(-100, 101))
         If ctr Mod 5 = 0 Then Console.WriteLine()
      Next
      Console.WriteLine()
      
      Console.WriteLine("20 random integers from 1000 to 10000:")      
      For ctr As Integer = 1 To 20
         Console.Write("{0,8}", rnd.Next(1000, 10001))
         If ctr Mod 5 = 0 Then Console.WriteLine()
      Next
      Console.WriteLine()
      
      Console.WriteLine("20 random integers from 1 to 10:")
      For ctr As Integer = 1 To 20
         Console.Write("{0,6}", rnd.Next(1, 11))
         If ctr Mod 5 = 0 Then Console.WriteLine()
      Next
   End Sub
End Module
' The example displays output similar to the following:
'       20 random integers from -100 to 100:
'           65   -95   -10    90   -35
'          -83   -16   -15   -19    41
'          -67   -93    40    12    62
'          -80   -95    67   -81   -21
'       
'       20 random integers from 1000 to 10000:
'           4857    9897    4405    6606    1277
'           9238    9113    5151    8710    1187
'           2728    9746    1719    3837    3736
'           8191    6819    4923    2416    3028
'       
'       20 random integers from 1 to 10:
'            9     8     5     9     9
'            9     1     2     3     8
'            1     4     8    10     5
'            9     7     9    10     5

下面的示例生成一个随机整数,该整数将用作索引以检索数组中的字符串值。 由于数组的最高索引小于其长度,因此该属性的值 Array.Length 作为 maxValue 参数提供。

using namespace System;

void main()
{
   Random^ rnd = gcnew Random();
   array<String^>^ malePetNames = { "Rufus", "Bear", "Dakota", "Fido",
                                    "Vanya", "Samuel", "Koani", "Volodya",
                                    "Prince", "Yiska" };
   array<String^>^ femalePetNames = { "Maggie", "Penny", "Saya", "Princess",
                                      "Abby", "Laila", "Sadie", "Olivia",
                                      "Starlight", "Talla" };
   
   // Generate random indexes for pet names.
   int mIndex = rnd->Next(0, malePetNames->Length);
   int fIndex = rnd->Next(0, femalePetNames->Length);
   
   // Display the result.
   Console::WriteLine("Suggested pet name of the day: ");
   Console::WriteLine("   For a male:     {0}", malePetNames[mIndex]);
   Console::WriteLine("   For a female:   {0}", femalePetNames[fIndex]);
}
// The example displays the following output:
//       Suggested pet name of the day:
//          For a male:     Koani
//          For a female:   Maggie
Random rnd = new Random();
string[] malePetNames = { "Rufus", "Bear", "Dakota", "Fido",
                          "Vanya", "Samuel", "Koani", "Volodya",
                          "Prince", "Yiska" };
string[] femalePetNames = { "Maggie", "Penny", "Saya", "Princess",
                            "Abby", "Laila", "Sadie", "Olivia",
                            "Starlight", "Talla" };

// Generate random indexes for pet names.
int mIndex = rnd.Next(0, malePetNames.Length);
int fIndex = rnd.Next(0, femalePetNames.Length);

// Display the result.
Console.WriteLine("Suggested pet name of the day: ");
Console.WriteLine("   For a male:     {0}", malePetNames[mIndex]);
Console.WriteLine("   For a female:   {0}", femalePetNames[fIndex]);

// The example displays the following output:
//       Suggested pet name of the day:
//          For a male:     Koani
//          For a female:   Maggie
let rnd = Random()

let malePetNames =
    [| "Rufus"; "Bear"; "Dakota"; "Fido";
        "Vanya"; "Samuel"; "Koani"; "Volodya";
        "Prince"; "Yiska" |]
let femalePetNames = 
    [| "Maggie"; "Penny"; "Saya"; "Princess";
        "Abby"; "Laila"; "Sadie"; "Olivia";
        "Starlight"; "Talla" |]

// Generate random indexes for pet names.
let mIndex = rnd.Next(0, malePetNames.Length)
let fIndex = rnd.Next(0, femalePetNames.Length)

// Display the result.
printfn "Suggested pet name of the day: "
printfn "   For a male:     %s" malePetNames.[mIndex]
printfn "   For a female:   %s" femalePetNames.[fIndex]

// The example displays output similar to the following:
//       Suggested pet name of the day:
//          For a male:     Koani
//          For a female:   Maggie
Module Example
   Public Sub Main()
      Dim rnd As New Random()
      Dim malePetNames() As String = { "Rufus", "Bear", "Dakota", "Fido", 
                                    "Vanya", "Samuel", "Koani", "Volodya", 
                                    "Prince", "Yiska" }
      Dim femalePetNames() As String = { "Maggie", "Penny", "Saya", "Princess", 
                                         "Abby", "Laila", "Sadie", "Olivia", 
                                         "Starlight", "Talla" }                                      
      
      ' Generate random indexes for pet names.
      Dim mIndex As Integer = rnd.Next(0, malePetNames.Length)
      Dim fIndex As Integer = rnd.Next(0, femalePetNames.Length)
      
      ' Display the result.
      Console.WriteLine("Suggested pet name of the day: ")
      Console.WriteLine("   For a male:     {0}", malePetNames(mIndex))
      Console.WriteLine("   For a female:   {0}", femalePetNames(fIndex))
   End Sub
End Module
' The example displays output like the following:
'       Suggested pet name of the day:
'          For a male:     Koani
'          For a female:   Maggie

注解

Next(Int32, Int32)重载返回介于-1 之间的随机 minValue 整数 maxValue 。 但是,如果 maxValue equals minValue ,则该方法返回 minValue

不同于方法的其他重载 Next ,后者仅返回非负值,此方法可以返回负随机整数。

继承者说明

从 .NET Framework 版本2.0 开始,如果从派生类 Random 并重写 Sample() 方法,则 Sample() Next(Int32, Int32) 如果和参数之间的差异大于,则不会将方法的派生类实现提供的分布用于方法重载的基类实现 minValue maxValue MaxValue 。 相反,将使用基类返回的统一分布 Random 。 此行为可改善类的整体性能 Random 。 若要修改此行为以调用 Sample() 派生类中的方法,还必须重写 Next(Int32, Int32) 方法重载。

另请参阅

适用于